Notes: Advanced PADI course, dive 5/5, “Underwater Naturalist”. Had to spot 5 vertebrates, 5 invertebrates and 2 plants. Average water temperature was 20 degrees celsius. Average depth was 10.9 m. I was very ill with sea sickness for this dive. I only went in because it was the last dive to get the Advanced PADI certificate and it would have been great hassle to repeat it at a later date. I had a headache throughout, even under water.

Notes: PADI advanced course dive 4/5, “Deep Dive”. Instructor demonstrated (i) colour dissipation under water (red almost gone at 25 m) and (ii) mental impairment at depth – the time to complete a simple mental task (picking out numbers from a grid in order) was measured at the surface and at 25 m. It took marginally longer at depth. Air is used at a rate proportional to depth.

Notes: Advanced PADI dive #2- “Underwater Navigation”. Did reciprocal line with (i) compass and (ii) natural features. Swam in a square by counting fins strokes and using compass. It took 40 seconds and 17 fin cycles to do 30 metres. Average depth was 6.7 m. Water temperature was 21 degrees celsius. Saw lots of sting rays.